Bell for blast furnaces



A. MOHR. JR., EITAL BELL FOR BLAST FURNACES Filed Oct. 9, 1943 PatentedApr. 16, 1946 UNITED STATES PATENT OFFICE BELL FOR BLAST FURNACES AlbertMohr, J r., and John P.-Grilli, Chicago, Ill.

Application October 9, 1943, Serial No. 505,639

- 4 Claims. (Cl. 214-36) In the charging equipment of an iron blastfurnace it is necessary to provide two bells to prevent the escape oftop gases from the furnace. These. bells are controlled so that only onehell is open at a time; that is, when one is open, the other is closed.

The top bell is designated as the small bell, and. is usuallyapproximately from four to seven feet in diameter, depending upon thesize of the furnace. The bell below the small bell is designated as thelarge bell, and has a diameter of approximately from thirteen to sixteenfeet, depending upon the size of the furnace.

The present invention is more. particularly directed to the large bell.With allpresent large bells the flow and distribution of materials fromthe large bell into the furnace is subject to many variables. It is ofparamount importance in the successful operation of the furnace, thatthe materials on the large bell flow into thefurnace at a uniform rate,and that the bell shall open equally around its entire circumstance;otherwise, the amount of materials will not be distributed uniformly,and this will preventthe furnace from attaining its best possibleperformance.

Such irregular distribution of 'the materials will cause the furnace towork hot on one side and cold on-the other side. At present the largebells are balanced after they are machined, but this balance is upsetafter the first few hours of operation. The reasons for the unbalancingof the large bell are the depositing of materials on the under side ofthe bell and the baking on of ore and other materials on the top side ofthe bell.

These materials do not deposit uniformly and are of different densities,and therefore throw the large bell out of balance, with the result thatthe large bell will be caused to open first on the side that the bell isheavy, thereby causing a greater amount of materials to be deposited inthe furnace on that side:

Another condition which causes the non-uniform. distribution of thematerials into the furnace is due to the fact that they bake on the topside of the bell, and they will slide off the bell on the cleaner sidefaster than on the baked section or side, thereby causing the large bellto swing. Thi condition is of such importance that in many plants thetop surface of the large bell is cleaned many times a day, by using barsand snappers to remove the baked-on materials.

In the accompanying drawing diagrammatically illustrative of thisinvention:

Fig. 1 shows a portion of a hopper and a large bell in position to closethe hopper.

Fig. 2 is a sectional view taken on line 2-.2, Fig. 1,, with partsomitted.

Fig. 3 is a fragmentary view of a portion of the hopper andlarge bell,showingjanother form of guiding means.

It is the usual practice in furnaces of this character to. suspend thelarge bell Ill from a bell rod H, which is approximately fifty feetlong, and the bell is always centered in the furnacewhen the latter iscold. Howeven'when the furnace is in generation there is an everchanging'tempera ture distribution within the furnace, and there aretimes when the center of the. large bell Ill, and theecenter of thebellfrod H at its point of suspension, are not in the same perpendicularaxes.

, This, of course, will cause the bell to swing, with the result thatthe bell will open on one side advance of the openingon the other side,and thereby cause unequal, distribution of materials in the furnace. i

It is one of the objects of the present invention to overcome thesedifficulties and objections, and to provide improved means for insuringthat the large bell will lee-prevented from so swinging, but will becaused to open uniformly about its entire circumference, therebyinsuring a uniform d'elivery cf thematerials into the furnace.

In carrying thisinventioninto use, the bell ill is shown connected tothe rodll, preferably by means of a key l2, and this large bellco-operates with a hopper l3. Supported within this hopper, preferablyby the wall thereof, are any suitable number of guide members 14 whichmay be secured in position in any suitable manner,

- and arepreferably of a wedge-shaped formation.

Carried by the bell Ill, preferably adjacent the circumferential edgethereof and outside of the bell, are additional guide members l5 whichmay be of any desired or suitable construction and configuration, andwhich may be secured in position in any suitable manner. It has beenfound, however, that the guides l 5 may be formed of rods or barssecured to the bell in any manner, such as by screwing one end of therods into the bell. These guide members I 5 are arranged uprightly, onein proximity to each of the guide members I4, and as the bell is openedby lowering the same with respect to the hopper, the guides I 5 willcooperate with the guide I 4, and thereby maintain the bell againstswinging, causing it to open evenly and to the same extent entirelyaround its circumference.

If desired, a plate or member l6 maybe provided to form a closure forthe bell itself, and this plate may be supported and secured in positionin furnace, and should the bell start to swing, the

guides l will strike the guides Land the bell will be maintained againstany such swinging movement.

The'plate' lfi forming a closure at the bottom' of the hollow bell, willprevent materials depositing upon it, because it will always be hot andabove the dew point of the gas leaving the stock of materials, as theinfluenceof the cold charge on the large bell will not keep this platecold.

The materials on top of the large bell will not bake on the top surfacethereof, because the plate or member It will prevent the gases in thefurnace from passing over the bottom surface of the large bell.

Inthe form of the invention shown inFigure 3, the guiding means forthebell consists of fins or members l9 secured to the outer face of thebell l0 adjacent the lower edge thereof, which, when the bell attemptstoswing while opening, will contact-the wall of the hopper and preventsuch attempted swinging movement. Any number of these members l9 may beprovided, and are suitably spaced around thecircumference of the bell.

While the preferred forms of the invention have been herein shown anddescribed, it is to be understood that various changes may be made inthe details of construction and in the combination and arrangement ofthe several parts, within the scope of the claims, without departingfrom the spirit of this invention.

What is claimed as new iszj 1. A blast furnace bell and hopper, saidbell adapted .to form a closure for the bottom of the hopper, means forsupporting and for moving said bell into open andclosed positions withrespect to r the. hopper, spaced Wedge-shaped'members secured to theinner face of the hopper adjacent the adapted to form a closure for thebottom of the hopper, means for supporting and for moving said bell intoopen and closed positions with respect to the hopper, spacedwedge-shaped members secured to the inner face of the hopper adjacent athe outlet end thereof, and upright guide bars secured to the bell andprojecting thereabove, said guide bars co-operating with the respectivewedge-shaped members to maintain the bell against tilting during itsopening movement, there being a space between the guide bars and therespective wedge-shaped members, whereby to maintain the charge in thehopper from wedging between the bars and the guide members.

3. A blast furnace bell and hopper, said bell adapted to form a closurefor the bottom of the hopper, means for supporting and for moving saidbell into open and closed positions with respect to the hopper, spacedwedge-shaped members secured to the inner face of the hopper adjacentthe outlet end thereof, upright guide bars secured to the bell andprojecting thereabove, said guide bars co-operating with the, respectivewedgeshaped members to maintain the bell against tilting during itsopening movement, said bell being hollow, and a closure for the openbottom of the bell.

4. A blast furnace bell and hopper, said bell adaptedto form a closurefor the bottom of the hopper, means for supporting and for moving saidbell into open and closed positions with respect to the hopper, spacedwedge-shaped members secured to the inner face of thehopper adjacent theoutlet end thereof, upright guide bars secured to the bell andprojecting thereabove, said guide bars co-operating with the respectivewedgeshaped members to maintain the bell against tilting during itsopening movement, said bell being hollow, and a corrugated closure forthe open bottom of the bell.

ALBERT MOHR, JR. JOHN P. GRILLI.

